1. Field of Invention
The present invention relates to a crank angle detection apparatus, and more particularly, to a crank angle detection apparatus in which a separate target wheel for detecting a crank angle is omitted.
2. Description of Related Art
In general, a crank angle sensor refers to a sensor which detects a rotation angle or a rotation position of a crankshaft of an engine.
The rotation angle (crank angle) of the crankshaft is an important parameter that determines ignition timing of the engine. For detecting a crank angle using the crank angle sensor, there are a method of directly detecting a rotation angle of the crankshaft and a method of estimating the crank angle from a rotation position of a distributor. Here, the distributor is a device for distributing high voltages generated in an ignition coil to spark plugs in order of ignition.
A method of detecting a signal from the distributor connected to an electric system is simple, but precision thereof is low. Therefore, a method of directly detecting a crank angle is mainly used in recent years.
However, if a separate target wheel, which is subject to detection by the crank angle sensor, is mounted at the crankshaft to directly detect the crank angle, a size and a weight of an engine may be increased. In addition, as processes of manufacturing the target wheel and mounting the target wheel at the crankshaft are added, the number of production processes for the engine may be increased. Moreover, components for mounting the target wheel at the crankshaft are required. Therefore, production costs for the engine may be ultimately increased.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.